Magnetic cap guide



April 1948- D. w. THOMAS 7 0, 0

MAGNETIC CAP GUIDE Filed May 1, 1946 3 Sheets-Sheet 1 w INVENTOR Jagjhs177%0/2145 B Y ,ATTORNEY' Ap 2 1948' D. w. THOMAS 2,440,030

MAGNETIC CAP GUIDE Filed May 1,1946 5 Sheets-Sheet 2 28 In;IIIIIIIiIIIIIIImIIIIiM lllllllllll III" M liimu jaqglas i 7/10/1145 w WATTORNEY 7'0 EL EC TR/C POWER L S OU/PCE A ril 20 1948.

p D. w. THOMAS MAGNETIC CAP GUIDE 3 Sheets-Sheet '5 INVENTOR Jag/a; i.Harms ATTORNEY Filed May 1, 1946 v Patented Apr. 20, 1 948 MAGNETIC CAPGUIDE Douglas W. Thomas, Englewood, N. 1., assignor to Boyle-MidwayInc., Jersey City, N. J a corporation of Delaware Application May 1,1946, SerialNo. 666,452

This invention relates to a magnetic cap guide adapted to form part of acontainer-capping machine. a

Numerous machines have been designed and used commercially for applyingscrew caps to bottles or other containers having threaded necks. In onetype, upright bottles are moved horizontally through the machine whilecaps are fed to the machine through a vertical or inclined chute. Aseach bottle passes under the mouth of the cap 6 Claims. (Cl. 226-88)chute, the forward edge of the bottle neck engages the inside of theforward part of a cap flange and the forward movement of the bottleextracts the cap from the chute and seats it in an approximatelyhorizontal position on the neck. As the bottle and cap pass on throughthe machine, they encounter rotating means which, by relative rotationof cap and bottle, turn the former home on the latter. In some machinesthe container is held relatively fixed and the cap is rotated; in othersthe cap is held fixed and the container rotated; in still others bothmay be rotated counter to each other.

Various types of mechanical guides have been devised to ensure that thecaps remain seated on the container necks as the containers pass fromthe cap chute to the cap-tightening means. One type of guide is in theform of an inverted rec- It is a .further object of my invention toprovide an eflicient magnetic cap guide for use with capsmade of orcontaining ferrous metal or other ferromagnetic material.

Other objects and advantages will be apparent from the followingdescription.

According to my invention I provide a magnetic guide in a cappingmachine extending above and parallelto the line of travel of thecontainers from the cap chute to or beyond the cap tightening means. Theguide is placed at such a height above the containers that caps, afterbeing removed from the chute by the forward movement of the containers,are attracted to the under side of the magnetic guide and held insliding contact with it, their sealing surfaces slightly above but theirlower flanges surroundingthe container necks. The caps are thus kept inperfect horizontal position and .alined with the necks of theirmagnetically attracted cap which requires horitangular trough, the sidesof which are provided on their bottom edges with narrow inwardlyextending flanges. These flanges are wide enough to support the caps bycontact with the bottom flanges of the caps, but spaced apartsufiiciently to permit passage of the container necks, each neck beingpartially inserted in a cap and moving the cap with it longitudinally ofthe trough as the container advances through the machine.

In spite of the small clearances involved andthe nice adjustmentrequired, such guides in general work satisfactorily provided bothcontainer and cap are made to close tolerances and are withoutimperfections.

In practice, however, it has been found that asubstantial percentage ofthe caps passing through such a machine either may land on the provide acap guide that will ensure proper seating of caps on containers in acapping machine.

It is another object of my invention to provide a guide of this kindthat is simple in construction and requires a minimum of closeadjustment in use.

zontal positioning and alinement with a container before tightening-e.g., friction caps or clampedon cap'sbut it is most useful andadvantageous for use with screw caps. In this case, as the caps come incontact with the tightening means they may be rapidly rotated relativelyto the container; the pushing contact of the container neck on theinside of the cap causes the threads of neck and cap'to engage and thecap is spun home. Since the cap is held horizontal by the magnetic guideas it engages the tightening means, crossing of threads is avoided andthe sealing surfaces of cap and container neck meet fairly to form atight seal. In various forms of machine, the cap may be spun while thecontainer is held, the container may be spun while the cap is held, orcap and container may both be rotated counter to each other. As the capis brought home on the container. neck, it is drawn down from contactwith the magnetic guide and further forward movement of the containerremoves it from the magnetic field of theiguide.

My guide may be a permanent magnet or an electromagnet energized by D.C. or A. C. current. I prefer to use an electromagnet since it is notsubject to demagnetization by vibration or heat when in use. A permanentmagnet, however, may be remagnetized from time to time as becomesnecessary. I prefer to make my guide in the form of two parallel iron orsteel strips bridged and connected by inverted U-shaped magnets withpoles all oriented in the same sense. The parallel strips thus becomepole pieces of opposite polarity. In the case of electromagnets the legsof the inverted Us are surrounded by coils of insulated wire wound inthe appropriate directions and connected with a source of electriccurrent. The Us maybeconnected in series or parallel, depending on thevoltage applied and the design of the windings. 'The field strength atthe pole pieces should be regulated to cause thecaps to jump intocontact with the guide as they leave the chute and to hold them there'with a moderate sliding pressure as they are moved towards thetightening means."

My magnetic guide is especially useful with caps stamped, spun orotherwise fabricated of iron, such as ferrous-base tin plate; it "can'al'so' I be used with caps of other paramagneticma terial, such forexample'as fnickelfby providing adequate field strength. While itispreferredit is not essential; that'the entirepapbeimade of paramagneticmaterial; Plastic; CQPSJJTQII'GXI-L' ample, with an iron washerlbetween'thegsealing' washer and the cap may be used' or caps con sisting of athreaded 'galvanized'flanged iron ring and a glass or plastic cover'may'be used; It is essential, however, that thegcapsused containsufficient material attracted owards-iithe"'magnetic field of the guideto'hold he ap'in'slidin'g' contact with the underside de. It is alsoessential that the topiofft soap 1' f with the magnetic guide be so shajed that"the types of caps with which it may be used are illus trated inthe accompanying drawings} the scope of my invention, however, is-n'ottobe' considered as limited thereby, but'is defined-in claims.

In the drawings:

appended is provided with a cap-retaining spring it having just,sufiicient tension to ensure that the caps do not drop out by gravitybutto permit each to be withdrawn from the chute by contact with theneck of an advancing container. For this purpose the chute is mounted atsuch a height that the lower forward edge of the bottom spring-held capis below the top of neck l5, as shown in Fig.3. a

The cap tightening means comprises two pairs of rapidly' rotated steeldiscs I! and H2. The discs of "each'pair are mounted on opposite sidesof the cap pathway, and each pair acts on each cap to screw it home onthe neck over which it is positioned, the second-pair of discs acting togive the caps a final'jtightening. Engagement of discs 'witncaps isensured by mounting the disc arbors for arcuate or sliding movement withsuitable'lirnitstops (e. g., l9)' and providing tension springs '20 and2l"toi'draw the discs of each pair towards each'other; Theedges'of'disc's l1 and la 'arejroughene'd 'by shallow fluting to effectfrictional rotation 'of the caps'by' the discs. DiscsIl"and';l8?arelrotated'by verticalspindles 22 and respectively. V Y

Power for operating belts 9,9, ii'l'and ii! and discs I! 'and I8 issupplied by prime mover 25 v locatedunder plate I and diagrammaticallyindi- Fig. ,1 isa plan view of that part-ofacapping machine embodyin myinvention:

Fig. 2 is a sectional sideview'of the part of the machine shown in Fig!1, the sectionuxcept as to the containers) being taken mun- 2 2 of Fig.1;'

Fig. 3 is alargerscale sectional sideview of'a portion of the machine.shoWn inFigJZ';

Fig. 4 is a sectional end view taken" on 'line d i of Fig. 3; and

Figs. 5 and 6 are sideviews partly'inisection of types of caps whichmaybe'usedf"with my' invention. a In the drawings, 1 represents amounted on supports'2 at a suitable he g the floor.Supports2"extend"aboveplateI and carry intermediate platei 3"in' 'atroughin 'which run chains 4 carrying articulatedfconveyorbelt 5 drivenby conventional means not shown. On 1 plate I are mountedposts'fiwhichextend through line flights of these belts'rlm horizontally above and oneach side ofconveyor .5, andact to keep containers l3 'in-lineasthe'ypass through the machine, the upper parts of the containersprojecting above and passingbetween plates-1. Y Ar-' rows indicatedirection oftravePof-conveyor, of

belts and of containers.

A cap chute is fixedly mountedx'abovethemachine having a forwardlyinclined'f'portion Id,-

terminating above the line of travel of container necks I5. The bottomofthe chute isopen but at approximately the same linear velocity as conveyor The magnetic 'guide which is the subject of this invention is"indicated" in general by 21. It consists essentiallybf two"narrow soft'iron strips 28"and 29,'inverted-U electromagnets connecting the stripsand inducing magnetic polarity'in them and supporting means to hold thestrip assembly above and parallel to conveyor 5:

The supporting: means includes two pairs of posts'30and'3l mountedonplates 1, and fixedly connected respectively by straight crossbar 32and'v crossbar 33: l The pole pieces areconn'ected together by screwedor riveted non-magnetic'battens (el'g; of'IBakelite) '34 and 35 inthecenters of 'which'iar 'mounted threaded non magnetic studs (eI g.; of'b'rass')'-36 and-3l passing through holes in crossbars32"and"33 whenthe guide is in position; The guide is maintainedat theproper height bywashers '38, hexagonal nuts 39 andwings" nuts 40: cooperatingwithcompression springs on both 'studs36 and 31, as shown in detail on'stud36 in Fig.3; This supporting means maintains the pole strips 28' and-29at a fixed minimum height abovethe conveyor but permits arlimited-amountof elastic displacement upwards to prevent binding and conform to slightoperating irregularities.-

The pole: pieces are provided with four pairs of electro-magnets 44;'Each (as shown for 4| in-'Fig.':4) consists of two soft iron corepieces 45 'and46"inclosemagnetic contact with pole pieces and 29 andwith soft iron yoke 41. Coils of'insulated wire 48- *surround the corepieces,

wound'ina suitable direction tovinduce opposite polarity in the polestrips '28 and 29 indicated byN-and'S. The coils'in each 'U unit areconnected by wire 49 and their opposite ends are conected by' leads 5!!to an electric power source through cable 5l.- The magnet units A i-Mmay be connected in series or inparallel, depending on windings; appliedvoltage, etc. In any case unitsM-M are'so'oriented' that all cooperateto magnetize eachpole piece; 28-or 29 respectively, in the same sense.

The machine illustrated in the drawings is set up for cappingrectangular containers having necks located on a center line. It will beobvious to those skilled in the art that alterations in the positioningof the tightening means and of the magnetic guide with respect toconveyor 5 and belts 9, 9, I and 10' may be made to accommodate varioussizes and shapes of container, e. g. rectangular containers with necksin a corner of the top.

The operation of the machine illustrated is as follows:

Containers placed on conveyor are advanced through the machine and keptalined by movement of the conveyor and of belts 9, 9', l0 and I0. Aseach container passes under chute I4 it removes the bottom cap from thechute by pressure of the forward edge of neck l5 on the inside of theforward edge of the cap flange; in chute 14 another cap then drops bygravity into the bottom position, and is retained there by spring I5until removed by a following container.

As soon as a cap is free of the bottom of the chute and. of spring 16,it drops on and partly surrounds the neck of the container which hasremoved it from the chute, but on further forward motion of thecontainer the cap is brought within the magnetic field of pole pieces 28and 29 and jumps into contact with them, assuming the position shown ata in Fig. 3. It will be seen that the cap is held horizontally and stillengages the neck of a container. In this position the cap is moved alongby the container to the tightening means. The only substantial work doneon the cap at this stage is that necessary to overcome the frictionbetween cap and guide :28 and 29, since the cap is not withdrawn fromthe pole pieces until it is screwed down by the tightening means.

When the cap engages the latter, viz, the successive pairs of discs I!and [8, it is rapidly rotated by them in a direction to screw it home onthe container; the slight pressure of neck on cap as each containeradvances causes the male and female threads to engage, and consequentlythe rotation of the cap brings it smartly home on the neck. Crossing ofthreads is prevented by the horizontal position of the cap as rotationstarts, and this horizontal position, in turn, is assured by themagnetic attraction of the cap to the horizontally disposed pole pieces28 and 29. Tightening of the cap draws it down and out of contact withthe pole pieces. Further advance of the capped container on conveyor 5expels the container from the machine.

The caps illustrated in Figs. 1-3 are of conventional ferrous-base tinplate. Other types of cap may be used with my invention provided theyincorporate a sufficient amount of paramagnetic material to be drawn upto pole pieces 28 and 29 with reasonably obtainable field strength. InFig. 5 is illustrated a cap having a plastic body, an elastic sealingwasher 53, and between the washer and the top of the cap a tinned irondisc 54 which furnishes a path for magnetic flux. Another usable type ofcap is shown in Fig. 6. This cap consists of a threaded iron ring 55,preferably galvanized or cadmium plated, provided with a retainingflange 56, which bears on plastic or glass top 51 when on the sealedcontainer to effect sealing through elastic washer 58. Ring 55 herefurnishes a path for magnetic flux.

As stated above, my magnetic guide is applicable not only in cappingmachines which apply screw caps to containers but also in those whichapply other types of caps such as friction caps; for example in such amachine a vertical plunger adapted. to drive the caps on the containernecks might replace spinning discs i1 and 18. In all such machines mymagnetic guide functions to maintain the caps in a desired angularrelation to the container at the moment of sealing.

I claim:

1. In a container-capping machine, captightening means, conveyor meansfor moving containers and caps into operative relation with thecap-tightening means, and a magnetic cap guide disposed in spacedparallel relation with the conveyor means ahead of the cap-tighteningmeans.

2. In a container-capping machine, captightening means, conveyor meansfor moving containers and caps into operative relation with thecap-tightening means, and a magnetic cap guide disposed in parallelrelation with the conveyor means ahead of the cap-tightening means, thedistance from the conveyor means to the magnetic cap guide being greaterthan the height of the containers but less than the added heights ofcontainer and cap.

3. In a container-capping machine, cap-supplying means, cap-tighteningmeans, conveyor means for moving containers and caps from thecap-supplying to the cap-tightening means, and a magnetic cap guideadapted to maintain caps in desired angular relation to containersduring travel to the cap-tightening means.

4. In a container-capping machine, captightening means, conveyor meansfor moving containers and caps into operative relation with thecap-tightening means, and a magnetic cap guide disposed in spacedparallel relation with the conveyor means ahead of the cap-tighteningmeans, said guide comprising two elongated spaced-apart pole pieces ofopposite polarity.

5. In a machine adapted to apply screw caps to containers havingthreaded necks, cap-supplying means, conveyor means, cap-tighteningmeans, and a magnetic cap guide, the cap-supplying means being adaptedto position successive caps on the necks of successive containerspassing therebeneath, the conveyor means being adapted to advancecontainers and associated caps from the cap-supplying means intooperative relation with the cap-tightening means, the cap-tighteningmeans comprising two like-rotating discs on arbors resiliently mountedso as to engage the discs with caps passing there-between and screw thediscs home on the associated container necks, and. the magnetic capguide comprising two elongated pole pieces of opposite polarityextending horizontally above the conveyor means and so positioned as tomaintain mganetically attracted caps in a horizontal position whilesurrounding the necks of containers and being brought into operativerelation with the cap-tightening means.

6. The combination defined in claim 5, in which the pole pieces areconnected by a plurality of inverted-U electrically energized magneticcores so oriented as to induce opposite magnetic polarity in the polepieces.

DOUGLAS W. THOMAS.

